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01-03-2013, 04:57 PM   #1
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How to Interpet ExposurePlot to find lens for next trip

How to Interpet ExposurePlot to find lens for next trip?

Photos were from a vacation/best liked photos
Lenses Used: Tamron 17-50 on K2000, Pentax 50-135 on K5
Expsoure Plot Graph is attached.

It appears that I used in APSC focal lengths- 17mm/50mm/135mm [25/80/200] the most.

My questions:

1. I am not sure if this is telling me that if I were to have something wider I would shoot wider and I if had something longer I would shoot longer. My only experience with wider is with the DA 15mm, a lens I like, but often find difficult to compose. Especially if I were travelling and were shooting more quickly than I like.

2. The next time I take a trip like this [a mixture of city and rural areas],would there be anything different I should take based on this graph? My travel kit is 2 cameras with a lens each. I donít change lenses during these kind of trips. Just my quirk for a variety of reasons. Is this telling me that I would have been better served with a 12-24 and 17-50 instead of the longer zoom? The 18-135 lens I have is probably one that fits my shooting style but the Plot also shows that I use f2.8 a lot which nixes that- a lot of those shots were people shots. Plus the 18-135 just does not match the other two lenses.

Maybe I am better off with the combo I use now?

Graph below shows focal length in blue, iso in red, aperture in orange and shutter speed in green:

Last edited by psychdoc; 11-14-2015 at 03:39 PM.
01-03-2013, 06:46 PM   #2
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I have found that a majority of shots are at either end of a zoom's range, just because that is the physical limit. Your FL graph supports this.
01-04-2013, 12:19 PM   #3
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I just have a K-x, but my two lens combo is the DA 18-135 and the Sigma 10-20.
If I have space and anticipate the need, I add the DAL 55-300.
01-04-2013, 01:14 PM   #4
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Seems to me you might learn more by looking at your pictures rather than at a graph. Do the pictures work for you, or not? Why?

Not rocket science. Not computer science. Just subjective judgements based on your artistic eye- if art is what you are seeking.


01-04-2013, 01:44 PM   #5
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The plot is telling you that if you had a wider lens you would probably used it.

It will be interesting to break up the plot into two, one for each lens and see which one was used most and how. There is a large spike at 80mm (50mm on APS-C) which is the upper/lower limit of your two lenses. The two plots will tell you if the spike is from the 17-50, the 50-135 or equally distributed. If it is from the 50-135, that also implies that you needed a wider than 50 lens at those times.

The tele end is not that pronounced so most likely you do not need much longer lengths. You can always crop the image for a tighter frame if needed.

From the F-stops, a lot of the images are taken wide open, indicating need for low light. On the other hand, most of the shots are at 100 ISO, so you can certainly go a bit slower than F2.8 by using 200 or 400 ISO and still maintain image quality.
01-04-2013, 01:56 PM   #6
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Thanks for the input all.
01-06-2013, 03:08 AM   #7
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If I'm travelling light and just for my pleasure not working, I've kinda standardised on just three lenses SMC Pentax-A 15mm F3.5, SMC Pentax-A 50mm F1.2 and SMC Pentax-A* 135mm F1.8.

Not vastly dissimilar to your lens choice and I get done what I need with just them, without any problems.
01-06-2013, 05:54 AM   #8
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Doing a city trip I take a 10-20 and a 28-75 that's all I need. In the country I add in a 70-200 plus a TC. I find an ultra wide is invaluable in a city


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